The maximum temperature a microwave can reach inside the cooking cavity typically depends on the power rating of the microwave oven. Most household microwave ovens have power ratings that range from 600 to 1200 watts, with some higher-end models going up to 1500 watts or more.
Microwave ovens are designed to heat food quickly and efficiently by using electromagnetic waves (microwaves) that excite the water molecules in the food, generating heat. The temperature inside the microwave cavity can rise rapidly, but it is limited by the boiling point of water (100 degrees Celsius or 212 degrees Fahrenheit) as water is the primary component of most food items.
When you cook food in a microwave, it's the water content that absorbs the microwaves and heats up, and eventually, the heat is transferred to the rest of the food. So, the temperature inside the microwave usually won't exceed the boiling point of water unless the microwave is malfunctioning or being used improperly.
It's worth noting that some microwave ovens come with additional features like grill or convection functions. In these cases, the temperature can go higher, as these functions use heating elements or hot air circulation to achieve higher temperatures for browning, crisping, or baking. However, the microwave mode itself typically won't exceed the boiling point of water due to its primary cooking mechanism.